I had good luck treating tenants in a nice way. Now, they all knew I was not a pushover by any stretch of the imagination. But, since you only have 3 tenants, I suggest you take time with each one separately to explain their options, and have them choose one.
They will learn that you aren't an ogre, and you'll have worked out something that will work for both of you. You can smile and stay firm, if they cry and beg you to continue picking up the check. Just be a smiling broken record, "No, I will not be picking up checks, so let's figure out which of these options will work best for you."
These tenants pay other bills. Ask them how they pay their other bills. If they say they get money orders and mail payments - there you go. If they say they walk their cash to each separate business, say, Okay, you can walk your cash to this bank and use these deposit slips, which I'll make sure you have a bunch of.
Your tenants may be afraid you will raise the rent or want to start renovating and have contractors coming and going, or that you will be difficult to work with, etc. You can calm their fears and keep good tenants and have a good rapport with them, with probably just an hour of your time where you are completely engaged with them, helping them to be comfortable with learning something new. Many people, and especially elderly people, or people from another culture, can be afraid of having to learn something new and feel or look stupid.
My job as a resident apartment manager, was to be a diplomat - as well as an enforcer. It's possible to be both. You'll have less problems and good relations, if they believe you are fair.
So, my vote is to come up with a few options that you are okay with - money order in the mail, direct deposit at the bank, Walmart's bill pay service. And, I'd include the cost for each one on your list of options. Yes, low-income people care if a service is free or $4.00. That's a loaf of bread.
Out of curiosity, I looked up the fees for the Walmart bill pay service, and they're really reasonable. I couldn't post the link because I'm a newbie, but I cut and pasted the fees. Congrats on inheriting tenants who pay their rent.
Oh, and as far as notice goes, I'd just make an appointment with them to give them their options to start next month. If they balk about proper notice, then deal with it then. They probably won't.
Walmart Bill Pay Fee Schedule:
- Standard (Delivered in 3 business days)Fee: $1.00
- Next Day (Delivered next business day*) Fee: $1.50
- Express Payments (Payment notification arrives in 10 minutes) Fees start at $3.95
- Money Order Fee: $0.70